无法对对象类型 ArrayList 实现 Filterable

Posted 2023-04-19

【中文标题】无法对对象类型 ArrayList 实现 Filterable

【英文标题】：Unable to implement Filterable to Object type ArrayList

【发布时间】：2020-11-12 09:55:15

【问题描述】：

我正在尝试在我的 recyclerview 中实现 Filterable，其中包含 <Object> 这是代码

private Filter exampleFilter = new Filter() 
    @Override
    protected FilterResults performFiltering(CharSequence constraint) 
        ArrayList<Object> filteredList = new ArrayList<>();
        if (constraint == null || constraint.length() == 0) 
            filteredList.addAll(mRecyclerViewItemsAll);
         else 
            String filterPattern = constraint.toString().toLowerCase().trim();
            for (Object item : mRecyclerViewItemsAll) 
                if (item.getVideo_name().toLowerCase().contains(filterPattern)) 
                    filteredList.add(item);
                
            
        
        FilterResults results = new FilterResults();
        results.values = filteredList;
        return results;
    
    @Override
    protected void publishResults(CharSequence constraint, FilterResults results) 
        mRecyclerViewItems.clear();
        mRecyclerViewItems.addAll((List) results.values);
        notifyDataSetChanged();
    
;

当我尝试上面的代码时，我得到cannot resolve method getVideo_name() in Object

那么我该如何实现Filterable。我在<String> 中使用了相同的代码，并且成功了。

回收站视图适配器：

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements Filterable 
    private static final int MENU_ITEM_VIEW_TYPE = 0;
    private static final int UNIFIED_NATIVE_AD_VIEW_TYPE = 1;

    private final Context mContext;
    private final ArrayList<Object> mRecyclerViewItems;
    ArrayList<Object> mRecyclerViewItemsAll;

    public RecyclerViewAdapter(Context context, ArrayList<Object> recyclerViewItems) 
        this.mContext = context;
        this.mRecyclerViewItems = recyclerViewItems;
        this.mRecyclerViewItemsAll = new ArrayList<>(recyclerViewItems);
    

    @Override
    public Filter getFilter() 
        return exampleFilter;
    
    private Filter exampleFilter = new Filter() 
        @Override
        protected FilterResults performFiltering(CharSequence constraint) 
            ArrayList<Object> filteredList = new ArrayList<>();
            if (constraint == null || constraint.length() == 0) 
                filteredList.addAll(mRecyclerViewItemsAll);
             else 
                String filterPattern = constraint.toString().toLowerCase().trim();
                for (Object item : mRecyclerViewItemsAll) 
                    if (item.getVideo_name().toLowerCase().contains(filterPattern)) 
                        filteredList.add(item);
                    
                
            
            FilterResults results = new FilterResults();
            results.values = filteredList;
            return results;
        
        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) 
            mRecyclerViewItems.clear();
            mRecyclerViewItems.addAll((List) results.values);
            notifyDataSetChanged();
        
    ;

    public class VideoAdapterViewHolder extends RecyclerView.ViewHolder
        
    

    @Override
    public int getItemCount() 
        return mRecyclerViewItems.size();
    

    @Override
    public int getItemViewType(int position) 
        Object recyclerViewItem = mRecyclerViewItems.get(position);
        if (recyclerViewItem instanceof UnifiedNativeAd) 
            return UNIFIED_NATIVE_AD_VIEW_TYPE;
        
        return MENU_ITEM_VIEW_TYPE;
    

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) 
        
    

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) 
        int viewType = getItemViewType(position);
        
    

    private void populateNativeAdView(UnifiedNativeAd nativeAd, UnifiedNativeAdView adView) 
        

这里是 MainActivity

@Override
    public boolean onCreateOptionsMenu(Menu menu) 
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.actionbar_menu, menu);
        MenuItem searchItem = menu.findItem(R.id.action_search);
        SearchView searchView = (SearchView) searchItem.getActionView();
        searchView.setImeOptions(EditorInfo.IME_ACTION_DONE);
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() 
            @Override
            public boolean onQueryTextSubmit(String query) 
                      return false;
                
              @Override
            public boolean onQueryTextChange(String newText) 
                recyclerViewAdapter.getFilter().filter(newText);
                      return false;
                
          );
        return true;
    

谁能帮助我做错了什么以及如何纠正它。

【参考方案1】：

无法解析 Object 中的 getVideo_name() 方法

您的列表是 Object 的类型，它是 Java 中的超类，不包含名为 getVideo_name() 的方法

对象类有预定义的方法，即：

toString()
hashCode()
clone()
equals(Object obj)
getClass()
finalize()
wait()
notify()
notifyAll()

您可以做的是创建默认为Object 类的子类型的类并定义类行为（方法）

例如：

class MyData 
    private String name;

    public String getVideoName() 
        return this.name;
    

    public void setVideoName(String name) 
        this.name = name;
    

然后像这样使用它：

private final ArrayList<MyData> mRecyclerViewItems;

【讨论】：

那我该怎么打电话

我在回收站视图中使用原生广告，所以如果我将表单 private final ArrayList<Object> mRecyclerViewItems; 更改为 private final ArrayList<MyData> mRecyclerViewItems; onBindViewHolder 上的 iget 错误

你必须到处改变。你在哪里使用或传递 list

我已经尝试过了，我面临这个问题***.com/questions/62983638/…